1. Field of the Invention.
This invention relates to book-like holders or albums, and specifically to a holder which is compact, economical, easy loading, having a durable hinge-like construction and creating a substantially dust-free environment for an article held therein, and also to a method for making such holders.
2. Description of the Prior Art.
Many prior conventional style albums or containers for cassettes (audio or video tape) have had a four-sided interior wall design and two tray PVC plastic parts (male and female) which are die cut into two separate sections. The two sections are then heat sealed into an album format. The male section acts as a regular tray that is heat sealed onto a plasticized vinyl back cover of the album, which houses the actual cassette. With this style, a cassette can only be loaded into the album by placing it within the four walls of the male tray section. The female tray section acts as a dust cover that is mounted inside the front cover of the album, and nests onto or into the back cover (male tray) to form a dust-proof enclosure album construction. The four inner walls of the male tray section hold the cassette in place, making it hard to load and unload the cassette. It also makes it hard to locate the front cover tray with the back cover tray when closing the album.
Such cassette albums have been formed by molding the PVC plastic tray sections in a multiple-up thermal forming stage, and then die cutting the two tray sections apart. The two tray sections are then taken into a heat sealing operation where they are bonded together with an outside vinyl lining which constitutes the album cover. Often, board liners are placed behind each tray section and also as stiffeners for the spine which is formed to bind the tray sections in a book-like manner. In the prior cassette albums, the tray sections were heat sealed (bonded) to the vinyl cover, with the hinges along the edges of the spine being two pieces of parallel bonded vinyl. Through normal wear and tear, and especially in cold weather conditions, this created a tendency for the vinyl to crack or split along the spine.
Examples of these types of vinyl-backed cassette containers are shown in the following patents:
______________________________________ U.S. Pat. No. Inventor Issued ______________________________________ 3,315,718 C. H. Berman 4/25/67 3,640,379 Weingarden 2/8/72 3,743,081 Roberg et al. 7/3/73 4,341,307 Shyers 7/27/82 ______________________________________
Another prior art holder is shown in U.S. Pat. Nos. 4,407,410 (issued 10/4/83) and 4,432,827 (issued 2/21/84), both to Graetz et al. The holder of this design had the trays formed from an inner thermoplastic sheet integrally with a spine liner between them. The inner sheet was then heat bonded to an outer thermoplastic cover sheet, but not along the length of the spine, and the spine bowed outwardly when the holder was closed. Even with this design, however, the inner sheet cracked along the spine.
The four wall construction of the album trays of such prior art cassette containers also created a constraint on the ability to reduce the size of such containers. Size is a critical feature in bulk storage of such containers and cassettes therein, and also in allotting shelf space in facilities which might use such containers, such as video cassette sale or rental stores.
In addition, no prior method was known for forming a book-like container which allowed for the use of transparent materials so that the edge of a cassette or the like contained therein is visible to the extent a bar code reader can be operated through the container to read coded information on the edge of the cassette itself. Such a feature is useful not only to create time savings in handling such album-contained cassettes, but also so that the cassette may be viewed to determine its contents and to determine whether it has been damaged or properly rewound.
Existing vinyl-backed cassette holders have thus been bulky, hard to load and unload, expensive and not sufficiently durable to hold up well in an environment where constantly handled, such as the retail video tape rental market.